The present invention is concerned with measuring the field current being conducted from an exciter to a generator via a pair of axial leads extending along the center of a shaft coupled to the generator and the exciter.
It is known to associate a wound rotor generator with an exciter which supplies a dc field current to the generator rotor via a pair of axial leads extending along the center of a shaft which is common to the exciter and the generator. It is desirable to be able to measure this field current in connection with monitoring generator performance, testing of generator transient response, detection of field winding shorts and diagnosis of excitation system malfunctions. However, in the case of certain types of generators, such as those having a brushless excitation system, the generator rotor field winding current cannot be measured directly.